1. Field of the Invention
The present invention relates to a method for reducing the resistance of a flying object that is carried by an aircraft or the like and is separated therefrom in the air.
2. Description of the Related Art
Forming the tip portion of a flying object as a thin elongated nose cone with a small tip angle is effective for reducing the air resistance of the flying object. However, the problem associated with thin elongated nose cones was that under conditions of limited accommodation space, the length of the main body had to be reduced which resulted in a decreased volume efficiency of the flying object and placed a limitation on the maximum load capacity thereof. Attempts to obtain a compact structure in the accommodation state by using a partially folded structure of the flying object in order to make the shape of the flying object as small as possible due to limited space for accommodating the flying object have been disclosed in Japanese Patent Application Laid-open No. 2001-141399 “Wing Unfolding Device of Flying Object” (published by Japanese Patent Office on May 25, 2001) and Japanese Patent Application Laid-open No. H8-226798 “Guided Flying Object” (Published by Japanese Patent Office on Sep. 3, 1996). The technological idea disclosed in Japanese Patent Application Laid-open No. 2001-141399 was to reduce the size and weight of a wing unfolding device for unfolding the wings in a flying object that is carried by and launched from an aircraft. For this purpose, after the flying object 2 has been launched, the aerodynamic load acting upon a parachute 7, which was released and opened rearward of the flying object 2, is transmitted to main wings 3a and 3b through hanging wires 8, thereby creating a rotation force. As a result, a lever 9 slides over the curved surface of a concave surface 8a, the main wings 3a and 3b rotate and unfold to the prescribed positions, and then the lever 9 fits into the concave surface 8b, thereby fixing the main wings 3a and 3b in their unfolded positions. Moreover, the configuration of the parachute 7 is such that after the main wings 3a and 3b have been unfolded, the parachute 7 creating aerodynamic resistance in flight is separated from the flying object 2 by the actuation of a delay cutter 11 after the prescribed time elapses. However, though the common feature of the above-described invention and the present invention is in increasing compactness in the accommodated state, it does not include the idea of reducing the air resistance of the flying object, which is essential for the present invention.
Japanese Patent Application Laid-open No. H8-226798 discloses a “guided flying object” having foldable and spreading wings developed with the aim of eliminating the unfolding mechanism or reducing the size thereof and obtaining a flying object that can be accommodated in a launcher cylinder, without placing a restriction on the size of the main body of the flying object, by using a combustion gas pressure of a rocket motor or an aerodynamic force created during flying, and also with the aim of reducing the resistance during flying and obtaining good aerodynamic characteristics. In the structure of such a guided flying object, as shown in FIG. 8, a spreading link mechanism 8 of the foldable and spreading wings is connected to a piston 7, the piston 7 is disposed inside a combustion gas inflow apparatus 10, and the wings are expanded by the pressure of the combustion gas of the rocket motor. This configuration allows the inertia force created by the control of the fuselage and an aerodynamic force created during flying to be used instead of the combustion gas pressure. The aim of this invention is to reduce the resistance during flying and to obtain good aerodynamic characteristic, but it relates to a rudder wing and does not improve the tip of the flying object.